A common feature of conventional offset presses with two-color printing capabilities, is the provision for the disengagement of one of the plate cylinders from the blanket cylinder, so that the user may optionally print using only one color. This allows the disengaged cylinder to remain idle as the one-color printing operation is performed.
One method for disengaging one of the two plate cylinders of a two-color press is demonstrated in the U.S. Pat. No. 2,845,860, to L. Mestre. In that patent the cylinders are moutted in slots within the frame of the press, and each can be shifted slightly so as to disengage the plate cylinder from the blanket cylinder. While this allows the use of the two-color press for one-color projects, it does nothing to simplify the task of cleaning or repairing the cylinders and inking apparatus in the press. Since the plate cylinders and various inking apparatus must be thoroughly cleaned in order to use different colors, it can be seen that it is desirable to provide an apparatus to enable the user to easily reach the cylinders and surrounding structure.
U.S. Pat. No. 3,521,559 to A. W. Sejeck, et al., demonstrates another method for disengaging one of the plate cylinders of a two-color press. The Sejeck device utilizes an auxiliary printing unit which is rockably affixed to the main frame of the conventional one-color press. While the auxiliary head may be "rocked" into a disengaged position, it remains in close proximity to the main frame so that it still remains a difficult task to reach the various cylinders for cleaning or repairs.
The applicant has a patent on an auxiliary print unit for use on a conventional one-color press, thereby creating the capability of the two-color printing. In that patent, U.S. Pat. No. 3,014,421, not only may a single cylinder be disengaged, but the auxiliary printing unit may also be completely removed from the press for repairs and the like. While this device gives complete access to both the main press and the auxiliary printing unit, it typically requires more than one person to remove the unit from the press, and an appropriate location to hold and store the auxiliary unit while removed from the press.
It is therefore an object of the present invention to provide an improved apparatus for disengaging an auxiliary printing unit from a one-color offset press.
Another object of the present invention is to provide a swing apparatus for an auxiliary print unit which allows the unit to be easily disengaged and swung aside by one person.
A further object is to provide a swing apparatus for an auxiliary print unit which will lift and swing the auxiliary unit away from the main unit for complete access to both the auxiliary unit and the main press.
An additional object of the present invention is to provide a swing apparatus which is powered to lift and swing the auxiliary unit from the press.
Still another object of the present invention is to provide a swing apparatus which is easily added to a conventional press having a removable auxiliary print unit.
Still a further object is to provide a swing apparatus which is simple in operation, economical to manufacture, durable in use and refined in appearance.
These and other objects will be apparent to those skilled in the art.